If a priest is in the state of mortal sin, can he still offer the Mass and perform the other sacraments?

When a sacrament is celebrated according to the norms of the Church and in faith, we believe that it confers the grace it signifies.  While a human being is the minister of the sacrament, Christ Himself is the one who is at work:  He baptizes, He confirms, He absolves, He changes the bread and wine into His Body and Blood, He unites a couple in marriage, He ordains, and He anoints.  Acting in His sacraments, Christ communicates the grace–   that sharing in the divine life and love of God– offered through each sacrament.  (Confer the Catechism, #1127-28.)

Therefore, the Church has taught that the sacraments act ex opere operato, that is “by the very fact of the action’s being performed.”  The efficacy of the sacrament does not depend upon the human minister– whether a bishop, priest, deacon, or layperson– being free of mortal sin and thereby in a state of grace.  Here then is the distinction between Christ who instituted the sacraments and acts through them to communicate His grace, and the human person who acts as Christ’s minister in performing the sacrament.

Actually this problem of the minister being in a state of grace and the efficacy of the sacrament emerged early in the Church.  Beginning in the year 311 in northern Africa, a dispute arose whether Bishop Caecilian of Carthage had been duly consecrated.  Allegedly, his consecrators had showed weakness during the time of persecution, thereby supposedly making them unworthy and unable to consecrate.  Donatus (270-355), heading the dissenting party, argued that Caecilian’s consecration as a bishop was invalid.  Moreover, this party’s platform, officially labeled the heresy of Donatism, asserted that the validity of a sacrament depends upon the minister’s holiness.

In 313, a special synod was held at the Lateran Palace in Rome to deal with this issue.  Donatus was condemned and excommunicated, not only for his heretical teaching but also for rebaptizing and ordaining apostates.  However, the heresy continued to plague the Church until Emperor Honorius renewed the condemnation of the Donatists and imposed severe civil sanctions against them in 411.

During this time, St. Augustine (354-430) was the great champion of true Catholic teaching.  In his In Ioannis evangelium tractatus, he forcefully distinguished the action of Christ versus the action of the minister when performing a sacrament:  Christ acts by His power, while the minister acts by his ministry entrusted to him by Christ.  Therefore, “…those whom Judas baptized, Christ baptized.  So too, then, those whom a drunkard baptized, those whom a murderer baptized, those whom an adulterer baptized, if the Baptism was of Christ, Christ baptized” (5,18).

Nevertheless, St. Augustine also sharply chastised the minister not properly disposed to perform the sacrament:  “As for the proud minister, he is to be ranked with the devil.  Christ’s gift is not thereby profaned: what flows through him keeps its purity, and what passes through him remains clear and reaches the fertile earth….  The spiritual power of the sacrament is indeed comparable to light:  those to be enlightened receive it in its purity, and if it should pass through defiled beings, it is not itself defiled.”  (In Ioannis evangelium tractatus, 5, 15).

The Church has continued to reassert this teaching, especially in those times of crisis.  In the Middle Ages, when clerical laxity was a problem in some areas, St. Thomas Aquinas (d. 1224) taught, “The sacrament is not wrought by the righteousness of either the celebrant or the recipient, but by the power of God” (Summa Theologiae, III, 68, 8).  In response to the objections of certain Protestant Reformers, the Council of Trent in its Decree on the Sacraments (1547) declared, “If anyone says that a minister in the state of mortal sin, though he observes all the essentials that belong to the performing and conferring of the sacrament, does not perform or confer the sacrament, anathema sit [“let him be condemned”].  Finally, the Catechism asserts, “From the moment that a sacrament is celebrated in accordance with the intention of the Church, the power of Christ and His Spirit acts in and through it, independently of the personal holiness of the minister” (#1128).

In all, the Church’s teaching is really spiritual common sense.  Christ who instituted the sacraments must be the one who actually works the sacrament, thereby giving us the assurance that the sacrament has indeed worked and conveyed the grace it signifies.  If the efficacy depended upon the human minister, how could anyone of us be assured that the sacrament worked and we received the promised grace?  Such assurance is not humanly obtainable.  Nevertheless, priests must strive always to be worthy ministers of the sacraments they celebrate, acting in a state of grace and reflecting the Christ in whose person they act.